MIDI Note Number Chart for iOS Music Apps
I’m regularly pulling this little chart up as I build music apps. I use it to translate scales and chords to numbers and to figure out what to name my samples.
Middle C in iOS
Middle C, in MIDI, is note number 60. Whether that note translates to C3 or C4 varies based on the platform.
With iOS and Apple’s sampler audio unit AVAudioSamplerUnit
, middle C is C4.
Impact of Middle C = C4
Apple’s sampler audio unit will automatically associate a sample to a MIDI note number based on the name of the audio file. This is where middle C = C4 becomes important.
If you have an audio file named piano_C4.wav
, and you load it into a sampler with sampler.loadAudioFiles(at: audioFileURLs)
, it’ll automatically get mapped to note number 60
.
To trigger the sample is just: sampler.startNote(60, withVelocity: 127, onChannel: 0)
.